Process for reversibly connecting a sensor to an inlet

ABSTRACT

The present disclosure relates to a process connection for connecting a sensor to a process inlet via a process seal and a fixing element. The process connection includes a sensor housing and a clamping element. The sensor housing has a housing body configured to receive the sensor and a housing collar that extends around the housing body and has a first sealing section, which encircles the housing body, and a contact area. The housing collar is formed integrally with the housing body. The first sealing section is suitable for receiving the process seal to connect the process inlet to the housing collar in a fluid-tight manner. The clamping element has a contact area which is suitable for coming into contact with the contact area of the housing collar to press the housing collar onto the process seal.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is related to and claims the priority benefit ofGerman Patent Application No. 10 2018 127 014.3, filed on Oct. 30, 2018,and U.S. patent application Ser. No. 16/668,936, filed Oct. 30, 2019,the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a process connection for a sensor andto a manufacturing method for such a process connection.

BACKGROUND

Process connections for sensors are used in a wide variety of industrialprocesses. Process connections serve to bring various kinds of sensors,for example a conductivity sensor, into contact with the process mediumof the process. The device carrying the process, for example a pipe orother container, has a process inlet for this purpose. The process inletand the process connection must be connected to each other in aleakproof and disconnectable manner. In order to achieve a leakproofclosure of the process inlet, a process seal is installed between theprocess connection and the process inlet. In addition, a fixing elementis used, for example a clamp, a screw or a union nut, in order toconnect the process connection to the process inlet in a disconnectablemanner. The fixing element presses the process connection onto theprocess seal in order to prevent the process medium from escaping. Thedisconnectable connection of process inlet and process connection makesmaintenance of the process connection or of the sensor possible.

Certain properties of the process connection and of the process inletare subject to various requirements, depending on the field ofapplication, which are defined by national and international standards(such as, for example, DIN 11851, DIN 11864-1, ISO 2852, etc.) orindustry quasi-standards of the application sectors (for example,“Varivent,” “Biocontrol,” etc.). Particularly in processes of the foodand beverage industry, there are strict regulations regarding thehygiene of process connections.

The hygienic properties of process connections are mainly affected byany gaps, edges or seals present, since deposits can easily form there.There are hygienic process connections which have, for example, fewseals, but which in turn only fit precisely one process inlet having aparticular diameter. However, since there is a multiplicity of processinlets each having different inlet diameters, the cost of realizing avariety of process connections for a sensor family is very high.

SUMMARY

An object of the present disclosure is to provide a process connectionfor a sensor which can deliver excellent hygienic properties and beusable for a plurality of process inlets in an economical manner.

This object is achieved by claim 1.

The present disclosure relates to a process connection for a sensor. Theprocess connection is suitable for being connected to a process inletvia a process seal and a fixing element. The process connection includesa sensor housing and a clamping element. The sensor housing has ahousing body and a housing collar. The housing body is designed toreceive the sensor. The housing collar extends around the housing bodyand has a first sealing section encircling the housing body and also hasa contact area. The housing collar is formed integrally with the housingbody. The first sealing section is suitable for receiving the processseal in order to connect the process inlet to the housing collar in afluid-tight manner. The clamping element has a contact area which issuitable for coming into contact with the contact area of the housingcollar in order to press the housing collar onto the process seal.

The process connection according to the present disclosure offers manyadvantages, wherein only a few advantages are to be mentioned below asexamples. One advantage which arises from the single-piece design of thesensor housing, especially, of the housing body and of the housingcollar, is that additional sealing points are avoided. On the one hand,there are thus fewer gaps in which deposits could form, which has anadvantageous effect on the hygienic properties of the sensor housing,and on the other hand, there are fewer elements to be maintained in theprocess connection. The advantage of a separate clamping element is thatthe clamping element can be used to receive the contact forces of thefixing element and transfer them to the sensor housing. The housingcollar can thus be optimized for the particular manufacturing method andadapted to the respective diameters of the process inlets. Thanks to theprocess connection according to the present disclosure, it is thuspossible to achieve flexible production and at the same time a reliablesealing effect.

According to one embodiment, the clamping element is annular and has anaxially circumferential first sealing section which is suitable forcontacting the process seal in order to connect the process inlet to theclamping element in a fluid-tight manner.

According to one embodiment, the process connection comprises an annularsealing element which is arranged between the sensor housing and theclamping element.

According to one embodiment, the annular sealing element is arrangedbetween the housing body of the sensor housing and the clamping element.

According to one embodiment, the first sealing section of the housingcollar is arranged on one end face at a radially outer end of theannular housing collar.

According to one embodiment, the first sealing section has one of thefollowing cross-sectional shapes: flat, conical or groove-shaped,especially, semicircular or rectangular.

According to one embodiment, the sensor housing has a transition regionwhich is arranged between the housing collar and the housing body andhas a radius between 3.2 mm and 6 mm or greater than 6 mm.

The present disclosure also relates to a manufacturing method for theprocess connection according to the present disclosure as claimed inclaim 8.

For a prespecified process inlet and for a prespecified process seal,the manufacturing method according to the present disclosure for theprocess connection according to the present disclosure comprises thefollowing steps: fabricating the sensor housing so that the housing bodyand the housing collar are integrally formed; adapting the housingcollar so that the housing collar has an outer diameter as well as afirst sealing section which are suitable for the prespecified processinlet and process seal; and fabricating the clamping element.

The manufacturing method according to the present disclosure has theadvantage that the sensor housing can be manufactured in amaterial-saving manner. A high-quality material can thus be used for thesensor housing without the production costs thereof being excessivelyburdened. By adapting the housing collar to the outer diameter of theprocess inlet, it is possible to adapt the sensor housing to any outerdiameter of a process inlet.

According to one embodiment, the sensor housing is manufactured byinjection molding.

According to one embodiment, the adaptation step of the housing collaris carried out by a separating method, for example a machining method.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is explained in more detail on the basis of thefollowing description of the figures in which:

FIG. 1 shows a cross-sectional view of a process connection according tothe present disclosure connected via a sealing ring to a processconnection;

FIG. 2 shows a cross-sectional view of an embodiment of the processconnection shown in FIG. 1 ;

FIG. 3 shows a detail view of FIG. 2 ;

FIG. 4 shows a cross-sectional view of an alternative embodiment of aprocess connection;

FIG. 5 shows a cross-sectional view of an alternative embodiment of theprocess connection shown in FIG. 2 ;

FIG. 6 shows a cross-sectional view of an alternative embodiment of theprocess connection shown in FIG. 2 ; and

FIG. 7 shows a cross-sectional view of an alternative embodiment of theprocess connection shown in FIG. 2 .

DETAILED DESCRIPTION

FIG. 1 shows a process connection 1 for a sensor. The process connection1 includes a sensor housing 10 and a clamping element 20. The processconnection 1 is configured for being connected to a process inlet 2 viaa process seal 3 and a fixing element 4 (shown in FIGS. 2 and 3 ).

The sensor housing 10 has a housing body 11 and a housing collar 12. Thehousing body 11 is designed to receive the sensor. The housing body 11enables the sensor to analyze a process medium through the process inlet2. If the sensor is, for example, an inductive conductivity sensor, themeasuring coils of the inductive conductivity sensor are enclosed by thehousing body 11 and can thus be immersed into the process medium, forexample, a liquid. In the case of an optical sensor, the housing body 11enables the sensor, for example, to have only optical access to theprocess medium.

The housing collar 12 extends around the housing body 11 as shown inFIGS. 1-7 . The housing collar 12 has a first sealing section 13 at aperiphery of the housing body 11. The first sealing section 13 isconfigured for receiving the process seal 3 to connect the process inlet2 to the housing collar 12 in a fluid-tight manner (e.g., liquid-tightor air-tight). The housing collar 12 is designed in such a way that thefirst sealing section 13 seats on the process seal 3 when the processconnection is fastened to the process inlet 2.

The housing collar 12 extends from the housing body 11. In oneembodiment, the housing collar 12 has a thickness between 2 mm and 3.1mm. This makes it possible to save material on the sensor housing 10.The material thickness of the housing collar 11 is selected depending onthe preferred manufacturing method to achieve a desired quality and/or adesired cost saving.

The housing collar 12 has a contact area 14. The contact area 14 isconfigured for experiencing a contact force so that the sensor housing10 is pressed onto the process seal 3.

The housing collar 12 is formed integrally with the housing body 11.Sealing points in addition to the process seal 3 are thus not needed.

The clamping element 20 of the process connection 1 has a contact area22, as shown in FIG. 1 . The contact area 22 is configured forcontacting the contact area 14 of the housing collar 12 in order topress the housing collar 12 onto the process seal 3.

As shown in FIG. 3 , the clamping element 20 is partially enclosed bytwo potential leakage paths L1, L2. The first leakage path L1 isharmless for a sensor arranged in the process connection 1 since theleakage path L1 cannot penetrate into the interior of the processconnection 1. The second leakage path L2 is potentially harmful for asensor arranged in the process connection 1 since the second leakagepath L2 does penetrate into the interior of the process connection 1.

The clamping element 20 is annular in that the clamping element 20 formsa closed ring. The radial cross-section of the annular clamping element20 can take any form.

The clamping element 20 has an axially circumferential first sealingsection 21 and an axially circumferential second sealing section 23 (seeFIG. 3 ).

The first sealing section 21 is configured for contacting the processseal 3 in order to connect the process inlet 1 to the clamping element20 in a fluid-tight manner. Due to the circumferential first sealingsection 21 of the clamping element 20, the clamping element 20 alsocomes into contact with the process seal 3 in addition to the sensorhousing 10 and thus forms a further sealing point between the interiorand exterior of the process seal 3 so that a sealing effect between thehousing collar 12 and the clamping element 20 is achieved only with thealready required process seal 3.

In an alternative embodiment (see FIG. 7 ), the clamping element 20 doesnot touch the process seal 3.

The second sealing section 23 is configured for contacting an annularsealing element 15. The annular sealing element 15 is disposed betweenthe sensor housing 10 and the second sealing section 23 of the clampingelement 20 (see FIGS. 2-4 ). The potential second leakage path L2 of theprocess medium between the clamping element 20 and the sensor housing 10is thus sealed. The process medium thus cannot penetrate into theinterior of the sensor housing 10 when the process seal 3 fails.

In one embodiment (not shown), the clamping element 20 has a leakagehole. The leakage hole is arranged between the first sealing section 21and the second sealing section 23 of the clamping element in such a waythat a process medium flowing along the second leakage path L2 is atleast partially discharged through the leakage hole. The leakage hole isconfigured for making visible to a user the discharge of the processmedium along the potential second leakage path L2.

The annular sealing element 15 is arranged, for example, between theclamping element 20 and the housing body 11, as shown in FIGS. 2-4 . Theannular sealing element 15 may have various cross-sectional shapes. Forexample, the annular sealing element 15 may be an O-ring seal. Theclamping element 20 is designed to precisely fit the housing body 11.The sensor housing 10 has a second sealing section 17 disposed on thehousing body 11 in order to come into contact with the sealing element15. The sealing element 15 may be, for example, an elastomer seal.

Alternatively, the sealing element 15, the second sealing section 23 ofthe clamping element 20, and the second sealing section 17 of the sensorhousing 10 can be arranged such that the sealing point formed by thesealing element 15 is formed between the clamping element 20 and thehousing collar 12 of the sensor housing 10 (not shown).

As shown in FIG. 4 , in an alternative embodiment of the processconnection 1, the first sealing section 13 of the housing collar 12 isarranged on an end face 18 of the housing collar 12. The end face 18 ofthe housing collar 12 is located at a radially outer end of the annularhousing collar 12.

The first sealing section 13 of the housing collar 12 may have variouscross-sectional shapes. For example, the first sealing section 13 may beflat or may be a groove (e.g., semicircular or rectangular). The processconnection 1 is thus suitable, for example, for process inlets 2 thatsatisfy the requirements of SMS 1147, DIN 11851 or ISO 2852.

The sensor housing 10 has a transition region 16 which is arrangedbetween the housing collar 12 and the housing body 11 and has a radiusbetween 3.2 mm and 6 mm or greater than 6 mm, which can be seenparticularly well in FIG. 3 . Alternatively, the transition region 16has a radius greater than 6 mm. This allows the process connection 1 tobe less susceptible to deposits of the process medium. The hygienicproperties of the process connection 1 are thereby improved.

The manufacturing method of the above-described process connection 1according to the present disclosure is now described below.

In a first step, the sensor housing 10 is manufactured. During thismanufacturing step, the housing body 11 and the housing collar 12 areintegrally formed. Manufacturing the housing body 11 and the housingcollar 12 as a single piece prevents gap formations at the processconnection and avoids additional sealing points.

The sensor housing 10 can be manufactured in such a way that the housingcollar 12 has an outer diameter D (as shown in FIG. 1 ) such that thesensor housing 10 is larger than the largest process inlet 2 of acategory of process inlets. Only a single “standard contour” of thesensor housing 10 thus needs to be manufactured for a plurality ofprocess inlets, which reduces manufacturing costs and non-productivetimes.

The sensor housing 10 may be manufactured by a primary forming method(e.g., casting), a forming method (e.g., pressure forming), a cuttingmethod (e.g., machining), or combinations of the aforementioned methods.

In order to manufacture the sensor housing 10, for example, a materialmay be selected from one of the following materials: thermoplastics,thermosets, polyether ether ketones, thermoplastic polyether etherketones, metal, ceramic or glass.

The sensor housing 10 is manufactured by an injection molding method,for example. This has the advantage that identical parts can bemanufactured cost-effectively in large numbers and closed sensorhousings can be produced in a hygienic design with a high degree offreedom of shape. Furthermore, a closed, seal-free surface can thus berealized with a high degree of freedom of design.

In a next step, the housing collar 12 is adapted in such a way that thehousing collar 12 has an outer diameter D, which is configured for aprespecified process inlet 2. This makes it possible to adapt thestandard type of sensor housing to a particular process inlet 2 in orderto achieve the maximum precision for the process connection 1. If thehousing collar 12 is to be adapted to the largest process inlet 2 of acategory of process inlets, the adaptation step serves to achieve ahigher accuracy of fit for the process inlet.

As shown in FIGS. 5-7 , the adaptation step of the housing collar 12also comprises the adaptation of the first sealing section 13 of thesensor housing 10 so that the sealing section 13 is configured forreceiving a particular process seal 3. The sealing section 13 is, forexample, flat, conical or groove-shaped, semicircular or rectangular.

For example, during the adaptation step, the first sealing section 13may be formed such that a molded seal in accordance with ISO 2852 may bereceived by the first sealing section 13 (see FIG. 5 ).

For example, during the adaptation step, the first sealing section 13may be formed such that a flat ring seal in accordance with SMS 1147 maybe received by the first sealing section 13 (see FIG. 6 ).

As a further example, during the adaptation step, the first sealingsection 13 may be formed such that a D-ring seal in accordance with DIN11851 may be received by the first sealing section 13 (see FIG. 7 ).

The adaptation step of the housing collar 12 takes place, for example,by machining the housing collar 12. This has the advantage of a highdegree of flexibility in material and geometry coupled with a higherprecision.

In a further step, the clamping element 20 is manufactured. The clampingelement 20 is manufactured in such a way that it is configured for thesensor housing 10 for the particular process inlet 2.

The clamping element 20 may be manufactured by a primary forming method(e.g., casting), a forming method (e.g., pressure forming), a cuttingmethod (e.g., machining), or combinations of the aforementioned methods.The manufacturing method for the clamping element 20 can also beselected depending on the manufacturing method selected for the sensorhousing 10.

For manufacturing the clamping element 20, a material is, for example,selected from one of the following materials: thermoplastics,thermosets, polyether ether ketones, thermoplastic polyether etherketones, metal, ceramic or glass.

The clamping element 20 is fabricated, for example, by a machiningprocess. This has the advantage that a flexible, requirement-appropriateselection of the material of the clamping element 20 and a highprecision in the manufacture of the clamping element 20 are achieved ata favorable cost.

Claimed is:
 1. A manufacturing method for a process connection adaptedfor reversibly connecting a sensor to a prespecified process inlet,which includes a fixing element and a process seal, the manufacturingmethod comprising: fabricating a sensor housing, which includes ahousing body and a housing collar formed integrally in one piece,wherein the housing body is fabricated to receive the sensor and suchthat the housing collar extends outwardly from a periphery of thehousing body, wherein the housing collar has an outer diameter, includesa first sealing section surrounding the housing body and includes acollar contact area; adapting the housing collar such that the housingcollar and the first sealing section are adapted and complementary tothe process inlet and process seal; and fabricating a clamping elementthat includes a clamping contact area configured to seat against thecollar contact area of the housing collar as to, in assembly, press thehousing collar against the process seal of the process inlet such thatthe sensor housing is connected to the process inlet via the housingcollar in a reversible, fluid-tight manner.
 2. The manufacturing methodclaim 1, wherein the sensor housing is fabricated by injection molding.3. The manufacturing method claim 1, wherein the clamping element isfabricated by casting, machining or a combination thereof.
 4. Themanufacturing method claim 1, wherein the sensor housing is fabricatedof a material comprising a thermoplastic, a thermoset, a metal, aceramic or a glass.
 5. The manufacturing method claim 4, wherein thesensor housing is fabricated of a material comprising polyether etherketone.
 6. The manufacturing method claim 1, wherein the adapting of thehousing collar is performed using a separating method.
 7. Themanufacturing method claim 6, wherein the adapting of the housing collaris performed using a machining method.
 8. The manufacturing method claim1, wherein the adapting of the housing collar includes reducing theouter diameter.
 9. The manufacturing method claim 1, wherein theadapting of the housing collar includes adapting the first sealingsection to be complementary to the process seal, wherein the processseal is configured to an industry standard, wherein in the industrystandard is one of ISO 2852, DIN 11851 and SMS
 1147. 10. Themanufacturing method claim 1, wherein the clamping element is fabricatedto be generally annular, having an axially circumferential clamp sealingsection configured to contact the process seal as to connect theclamping element to the process inlet in a fluid-tight manner.
 11. Themanufacturing method claim 1, wherein the sensor housing is fabricatedsuch that the first sealing section of the housing collar is disposed onan end face at a radially outer end of the housing collar, which isgenerally annular.
 12. The manufacturing method claim 1, wherein thesensor housing is fabricated such that the first sealing section has aflat, conical, groove, semicircular or rectangular cross-sectionalshape.
 13. The manufacturing method claim 1, wherein the sensor housingis fabricated such that the sensor housing includes a transition regiondisposed between the housing collar and the housing body, the transitionregion having a radius of between 3.2 mm and 6 mm or greater than 6 mm.14. The manufacturing method claim 1, wherein the sensor housing isfabricated such that the sensor housing includes a transition regiondisposed between the housing collar and the housing body, the transitionregion having a radius of greater than 6 mm.
 15. The manufacturingmethod claim 1, further comprising introducing the sensor into thehousing body of the sensor housing.
 16. The manufacturing method claim1, further comprising: introducing the sensor into the sensor housing;introducing the housing body of the sensor housing into the processinlet such that the first sealing section seats against the processseal; applying the clamping element to the sensor housing such that theclamping contact area of the clamping element seats against the collarcontact area of the housing collar as to press the housing collaragainst the process seal of the process inlet; and applying the fixingelement to the clamping element such that the sensor housing isconnected to the process inlet via the housing collar in a reversible,fluid-tight manner.